JP2001097206A - Negative pressure type booster device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a negative pressure type booster which improves the working efficiency of assembly. SOLUTION: A housing 2, a movable wall 3, a power piston 6, an input member 8, a valve mechanism 9, and an output rod 1 are provided.
1, an auxiliary movable wall 15, and a negative pressure booster 1 including a diaphragm 16 forming an auxiliary variable pressure chamber 17 between the auxiliary movable wall, the communication connecting the rear chamber 5 and the auxiliary variable pressure chamber 17. Passage 81, rear chamber 5 and auxiliary chamber 1 via communication passage 81
And a solenoid valve 20 capable of cutting off communication with the solenoid valve 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum booster for assisting a braking force, and more particularly to a vacuum booster applied to an automobile.

[0002]

2. Description of the Related Art As a conventional negative pressure booster, for example, as disclosed in U.S. Pat. No. 5,890,775, there is provided a housing having at least one pressure space formed therein, and a housing in the housing. A movable wall which is installed so as to be able to move forward and backward with respect to the housing and divides the pressure space into a front chamber communicating with a negative pressure source and a rear chamber selectively communicating with the front chamber and the atmosphere; A power piston coupled to the movable wall, an input member disposed inside the power piston so as to be able to move forward and backward with respect to the power piston, and movable by operation of an operation member; and movement of the input member. A valve mechanism including a negative pressure valve that communicates the rear chamber with the front chamber and an atmospheric valve that communicates the rear chamber with the atmosphere in response to movement of the input member, and a valve mechanism that moves with the movable wall. An output member that is advanced by a forward movement of the war piston and outputs the forward force of the power piston to the outside of the device; and an output member that is disposed in the front chamber so as to be movable in the front-rear direction and engages with the output member. An auxiliary movable wall that is movable in the front room, a partition member that forms an auxiliary room between the auxiliary movable wall and the auxiliary movable wall, and connects the auxiliary room to the rear room or the connection room via the connection pipe. And a valve mechanism communicating with the atmosphere.

[0003]

However, the above-described conventional vacuum booster has a structure in which the auxiliary chamber is communicated with the atmosphere in the vehicle cabin through the connecting pipe by the valve mechanism. In the assembling process, a complicated process is required, which hinders improvement in work efficiency. In addition, an increase in the output of the negative pressure booster due to the auxiliary movable wall is a so-called high jump output method in which a constant output is increased, and the output increase in a low input range is very inconvenient.

[0004] It is a first technical object of the present invention to provide a negative pressure type booster which improves the working efficiency of assembly. In addition, the second technical problem of the present invention is to provide a negative pressure booster capable of obtaining an output easily adapted to a driver by increasing an output by an auxiliary movable wall according to an input. I do.

[0005]

According to a first aspect of the present invention, there is provided, as a first means, a housing having at least one pressure space formed therein, and a housing formed in the housing with respect to advancing and moving with respect to the housing. A movable wall that is installed so as to be able to retreat and divides the pressure space into a front chamber that communicates with a negative pressure source and a rear chamber that selectively communicates with the front chamber and the atmosphere; A power piston, an input member disposed inside the power piston so as to be able to move forward and backward with respect to the power piston, and movable by operation of an operation member; and the rear chamber in accordance with the movement of the input member. A valve mechanism having a negative pressure valve communicating with the front chamber and an atmosphere valve communicating the atmosphere with the rear chamber in response to the movement of the input member, and a forward movement of the power piston accompanying the movement of the movable wall. An output member that is advanced to output the forward force of the power piston to the outside of the device; and an auxiliary member that is disposed in the front chamber so as to be movable in the front-rear direction and that can move the output member by engaging with the output member. In a negative pressure booster including a movable wall and a partition member disposed in the front chamber and forming an auxiliary chamber between the auxiliary movable wall, the rear chamber and the auxiliary chamber can be communicated with each other. Thus, a negative pressure type booster was constructed.

Preferably, as a second means, a communication passage for communicating the rear chamber with the auxiliary chamber, and a first valve capable of cutting off communication between the rear chamber and the auxiliary chamber via the communication passage. A negative pressure type booster of the first means, characterized by comprising a mechanism, is desirable.

Preferably, as the third means, the first means
It is preferable that the valve mechanism be capable of selectively communicating the auxiliary chamber with the negative pressure source or the rear chamber.

Preferably, as the fourth means, the first means
The valve mechanism is actuated according to the condition of the vehicle to communicate the auxiliary chamber and the rear chamber.
The negative pressure booster of the third means or the third means is preferable.

Preferably, as a fifth means and a means for solving the second technical problem, the first valve mechanism is operated by a driver to connect the auxiliary chamber and the rear chamber with each other. It is preferable that the vacuum booster of the second or third means is characterized in that it is communicated.

Preferably, as a sixth means, the first valve mechanism is disposed in the communication passage and between the first valve mechanism and the rear chamber, and when the rear chamber has a predetermined pressure. The negative pressure booster according to any one of the second means to the fourth means, further comprising a second valve mechanism for communicating between the second chamber and the rear chamber.

In the negative pressure type booster of the first means, the rear chamber and the auxiliary chamber can communicate with each other.

In the negative pressure booster of the second means, in addition to the function of the first means, the communication between the rear chamber and the auxiliary chamber via the communication passage can be cut off by the first valve mechanism.

In the negative pressure booster of the third means, in addition to the function of the second means, the auxiliary chamber can be selectively communicated with the negative pressure source or the rear chamber by the first valve mechanism. .

[0014] The negative pressure type booster of the fourth means is characterized in that, in addition to the action of the second means or the third means, the first valve mechanism is actuated according to the situation of the vehicle so that the auxiliary chamber and the auxiliary chamber are connected. Communicate with the rear room.

[0015] In the negative pressure booster of the fifth means, the first valve mechanism is actuated by the driver to make the auxiliary chamber communicate with the rear chamber.

The negative pressure type booster of the sixth means has the function described in any one of the second means to the fourth means. The first valve mechanism and the rear chamber can be communicated by the valve mechanism.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments.

(Embodiment 1) FIG. 1 is a sectional view of a vacuum booster 1 according to an embodiment of the present invention. As shown in FIG. 1, a housing 2 of a negative pressure type booster 1 is provided with a movable wall 3 whose outer peripheral portion is hermetically fixed and movable in the axial direction.

The interior of the housing 2 is airtightly separated from the front chamber 4 and the rear chamber 5 by the movable wall 3. The front chamber 4 communicates with an intake manifold of a vehicle (not shown), which is a negative pressure source, via an inlet 2a,
Negative pressure is always generated.

A power piston 6 made of a resin material is inserted into the housing 2 from the rear thereof, and the movable wall 3 is airtightly fixed to the power piston 6 at an inner peripheral end thereof. Inside the power piston 6, there is inserted an input rod 7, which is a brake operation member of the vehicle, for example, connected to a brake pedal 80 at a rear end (right side in FIG. 1). The input rod 7 is connected to an input member 8 described below so as to be integrally movable.

The input member 8 has a function of transmitting the brake operation force from the input rod 7 to the reaction disk 10. The output rod 11 in contact with the reaction disk 10 receives the brake operation force via the reaction disk 10 and moves to operate the piston of the master cylinder 71. Further, a stopper 24 having a claw 24a for restricting the relative movement of the output rod 11 to the front of the power piston 6 (to the left in FIG. 1) is provided on the power piston 6.

A rod retainer for receiving the return spring 12 is fixed to the input rod 7. The power piston 6 has a control valve 1 that constitutes a valve mechanism 14.
3 are provided.

FIG. 2 is an enlarged view of the valve mechanism 14 shown in FIG. As shown in FIGS. 1 and 2, the valve mechanism 14 is
An atmosphere valve V1 for communicating or shutting off the air with the atmosphere, and a negative pressure valve V2 for communicating or shutting off the front chamber 4 and the rear chamber 5 are provided.

The atmosphere valve V1 has an annular atmosphere valve seat 8a integrally formed at the rear end of the input member 8 and facing rearward (rightward in FIG. 2), and an atmosphere valve seat at the front end of the control valve 13. 8a, the communication between the rear chamber 5 and the atmosphere is cut off by abutting on the atmosphere valve seat 8a, and the atmosphere valve seat 8a
And an atmosphere seal portion 13a that communicates the rear chamber 5 to the atmosphere by being separated from the atmosphere.

The negative pressure valve V2 is disposed opposite the negative pressure valve seat 6a at the front end of the control valve 13, and is in contact with the negative pressure valve seat 6a. By rear room 5 and front room 4
And a negative pressure seal portion 13b that disconnects the rear chamber 5 from the front chamber 4 by disconnecting from the negative pressure valve seat 6a.

Atmospheric seal 13a and negative pressure seal 13b
The front end portion of the control valve 13 including the above is urged forward by a valve spring 13c.
With the above configuration, the atmosphere sealing portion 13a is in contact with the atmosphere valve seat 8a when the input rod 7 is in a non-operating state. When the input rod 7 is in the operating state, the negative pressure seal portion 13b can contact the negative pressure valve seat 6a.

Keyway 6d installed in power piston 6
The key 14 is inserted into the housing 2 and is in contact with the housing 2 via a damper member. Further, the power piston 6 is provided with a vacuum path 6b and an air path 6c.

In the rear chamber 5, an auxiliary movable wall 15 engageable with the flange portion 11a of the output rod 11 at an inner peripheral portion thereof.
The auxiliary movable wall 15 is hermetically engaged with a diaphragm 16 provided with a sealing bead 16a on the inner peripheral portion and the outer peripheral portion thereof, in particular, the inner peripheral side bead 16a.
Are slidably fitted to the auxiliary movable wall 15 and form an auxiliary transformer chamber 17 therebetween.

The auxiliary movable wall 15 receives a biasing force from the housing 2 by a return spring 18. A telescopic air passage 19 airtightly connected at one end to the auxiliary movable wall 15 passes through the front chamber 4 and airtightly engages the front surface of the housing 2 at the other end.

The air passage 19 is connected to the auxiliary transformer chamber 18 and the solenoid valve 20.
(First valve mechanism). The back room 5 is a pipe 2
It is connected to the solenoid valve 20 via the b communication pipe 81.

FIG. 3 is an enlarged sectional view of the solenoid valve 20 shown in FIG. As shown in FIGS. 1 to 3, a solenoid valve 20 has a constant pressure port 2 connected to a front chamber 4 in a valve housing 20 a.
0b, an air port 20c connected to the air port 201 connected to the communication pipe 81 via a cleaner member, and a transformation port 20d connected to the air path 19. The electromagnetic solenoid 20e is connected to a power supply of a vehicle (not shown) by a terminal, and is operated by being supplied with power from the power supply by a controller 84 of the vehicle.

In the valve housing 20a, a plunger 20f is disposed inside the electromagnetic solenoid 20e so as to be movable in the front-rear direction (the left-right direction in FIG. 3).
Further, a valve body 20h is disposed rearward (rightward in FIG. 3) of the plunger 20f and coaxially with the plunger 20f so as to be movable in the front-rear direction.

The plunger 20f and the valve body 20h are forwardly moved by the springs 20g and 20i (left side in FIG. 3).
Has been energized. As the plunger 20f retreats, the rear end of the plunger 20f engages with the front end of the valve 20h, and the valve 20h is pushed rearward by the plunger 20f. That is, the valve element 20h can be retracted integrally with the plunger 20f.

In the initial state shown in FIG. 3, since the plunger 20f and the valve body 20h are urged forward by the springs 20g and 20i, the valve body 20h is in contact with the atmospheric valve seat 20j. In this state,
Since the valve element 20h is disengaged from the constant pressure valve seat 20k, the auxiliary variable pressure chamber 17 is provided inside the air passage 19, the variable pressure port 20d, the clearance between the valve element 20h and the constant pressure valve seat 20k, and the constant pressure port. It communicates with the front room 4 via 20b.

On the other hand, when the power is supplied from the power supply to the electromagnetic solenoid 20e by the controller 84 of the vehicle as described above, the electromagnetic solenoid 20e becomes the plunger 20f.
Of the plunger 20f and the valve body 2
0h is moved backward against the biasing force of the springs 20g and 20i to bring the valve body 20h into contact with the constant-pressure valve seat 20k and disengage with the atmospheric valve seat 20j. Thus, the auxiliary transformer chamber 17 is connected to the air passage 20, the transformer port 2
0d, clearance between the valve body 20h and the atmospheric valve seat 20j,
It communicates with the rear chamber 5 through the atmosphere port 20c, the air cleaner, the atmosphere port 201, the communication pipe 81, and the pipe 2b.

The operation of the vacuum booster 1 will be described below. When the driver does not operate the brake pedal 80, which is a brake operation member of the vehicle, the vacuum booster 1 is in the state of FIGS. 1 and 2 and the atmosphere seal portion 13a is the atmosphere valve seat of the input member 8. 8a, and the negative pressure seal portion 13b is not engaged with the negative pressure valve seat 6a of the power piston 6. Therefore, the rear chamber 5 is provided with an air path 6c, a clearance between the negative pressure valve seat 6a and the negative pressure seal portion 13b, a vacuum path 6b, and an intake manifold of a vehicle engine (not shown) that is a negative pressure source via the front chamber 4. Is in communication with

FIG. 4 is a characteristic diagram of the vacuum booster 1 of the present embodiment in which the vertical axis represents the output and the horizontal axis represents the input. As shown in FIGS. 1 to 4, when the driver depresses the brake pedal 80 with, for example, the input FiX, the input rod 7 connected thereto receives a brake operation force and moves forward (to the left in FIG. 1). Go to Therefore, the input member 8 fixed to the input rod 7 also moves forward integrally with the input rod 7.

The movement of the input member 8 causes the atmospheric seal portion 13a and the negative pressure seal portion 1 of the control valve 13 to move.
1 also moves forward in FIG. 1 together with the input member 8 by the urging force of the valve spring 13c, and the negative pressure seal portion 13b eventually comes into contact with the valve seat 6a of the power piston 6, and the rear chamber 5 is cut off from the front chamber 4. Therefore, communication with the negative pressure source of the vehicle is also cut off.

Further, when the input member 8 moves forward, the engagement between the atmosphere sealing portion 13a and the atmosphere valve seat 8a is released, and the rear chamber 5 is closed with the rear opening and the inside of the power piston 6 and the atmosphere sealing portion. It communicates with the atmosphere via a clearance between the portion 13a and the atmosphere valve seat 8a and the air path 6c. Therefore, the inflow of the atmosphere into the rear room 5 causes the front room 4 and the rear room 5
The movable wall 3 and the power piston 6 connected to the movable wall 3 receive a load due to the pressure difference.
The amplified braking force is output to the output rod 11 via the reaction disk 10.

Thereafter, the reaction force received by the input rod 7 from the reaction disk 10 via the input member 8 causes the atmospheric seal portion 13a and the atmospheric valve seat 8a or the negative pressure seal portion 13b and the negative pressure valve seat 6a to move. Are selectively engaged, and the assisting force of the vacuum booster 1 is controlled in accordance with the driver's braking force applied to the input rod 7.

The reaction force due to the braking force of the power piston 6 and the brake operation force generated by operating the brake pedal 80 and transmitted to the input member 8 are applied to the reaction disk 10 and balanced.
When the braking operation force, that is, the input FiX and the reaction force from the reaction disk 10 are balanced, the output output from the output rod 11 is FoX shown in FIG.

In this state, since the electromagnetic solenoid 20e of the electromagnetic valve 20 is not operated, the auxiliary transformer chamber 1
Numeral 7 communicates with the front room 4, there is no pressure difference before and after the auxiliary movable wall 15, and the auxiliary movable wall 15 is in a non-operating state. Accordingly, the trajectory of the output with respect to the input of the negative pressure type booster 1 during the normal brake operation follows the diagram A in FIG.

For example, an obstacle appears in front of the vehicle, and the driver depresses the brake pedal 80 with the input Fix, and the controller 84 of the vehicle detects, for example, the pedal stroke value detected by the pedal stroke switch 83 attached to the brake pedal 80. Based on the brake pedal 80
When it is determined that an emergency brake is necessary when it is detected that the pedal has been operated at a pedal stroke speed equal to or greater than a certain threshold, when the necessity of the emergency brake is determined, power is supplied separately from the driver's brake operation. From electromagnetic solenoid 2
0e is supplied with power.

That is, in the negative pressure type booster 1, the normal operation by the driver's brake operation and the automatic operation by the operation of the solenoid valve 20 are performed. The electromagnetic solenoid 20e receiving the electric power generates an electromagnetic force to move the plunger 20f and the valve body 20h to the springs 20g and 20g.
It is moved rearward (rightward in FIG. 3) against the urging force of i.

As described above, the auxiliary transformation chamber 17 is communicated with the rear chamber 5 by the movement of the plunger 20f and the valve body 20h, and the rear chamber 5 is communicated with the atmosphere as the driver depresses the brake pedal 80. Therefore, the atmosphere is also introduced into the auxiliary transformation chamber 17. Due to the introduction of the atmosphere into the auxiliary transformer chamber 17, a pressure difference occurs before and after the auxiliary movable wall 15, and the auxiliary movable wall 15 is moved forward while sliding on the inner periphery of the bead 16a.

As the auxiliary movable wall 15 moves,
The auxiliary movable wall 15 is engaged with the flange portion 11a of the output rod 11 to apply a load forward to the output rod 11, but since this load does not act on the reaction disk 10,
It does not become a reaction force to the input member 8, but is purely increased as the brake output.

Accordingly, the output of the vacuum booster 1 at this time is the sum of the input from the driver and the forward force of the power piston 6 and the forward force of the auxiliary movable wall 15 during normal operation. That is, the brake output acting on the output rod 11 changes from FoX to FoX 'for the same brake operation force FiX acting on the input rod 7 as compared to when the pressure in the auxiliary transformation chamber 17 is negative due to the introduction of the atmosphere into the auxiliary transformation chamber 17. Be increased.

In other words, the trajectory of the output with respect to the input of the negative pressure booster 1 in the rapid braking operation follows the operation line B in FIG.

When the driver of the vehicle judges that the necessity of the brake operation is no longer necessary and returns the brake pedal 80 of the vehicle, the input member 8 moves backward by retreating the input rod 7, and the atmosphere seal portion 13a is moved to the input member. 8 and the negative pressure seal portion 13b is separated from the negative pressure valve seat 6a of the power piston 6, so that the rear chamber 5 is cut off from the atmosphere and communicates with the front chamber 4.

As a result, the degree of negative pressure in the rear chamber 5 increases again, so that the assisting force for the power piston 6 also decreases, and the reaction force from the master cylinder 70 and the return spring 18 in the booster 1 cause the power piston 6 and the input rod 7 are moved backward, and the return stroke is completed by releasing the input.

At that time, a brake pedal 80 (not shown)
When the microcomputer 84 detects that the brake operation has been released by the conventional brake switch installed in the electromagnetic solenoid 20e, the supply of power from the power supply to the electromagnetic solenoid 20e is stopped, and the electromagnetic solenoid 20e is no longer connected to the plunger 20f. Plunger 2 without generating electromagnetic force
0f and the valve element 20h are returned forward by the urging force of the springs 20g and 20i. By the forward movement of the plunger 20f, the auxiliary transformer chamber 17 communicates with the front chamber 4 again, and the auxiliary movable wall 15 is pushed back by the return spring 18, and its inner peripheral end and the flange portion 1 of the output rod 11 are moved.
1a is released and completely returned to the initial state.

The difference (Fox'-Fox) between the output FoX on the operating line A and the output FoX 'on the operating line B at the same input FiX increases as the input increases. This is because the pressure in the rear chamber 5 increases as the input increases, and the pressure in the auxiliary transformation chamber 15 communicating with the rear chamber 5 also increases as the input increases. .

As described in the above embodiment, according to the present invention, when air is introduced into the auxiliary transformer chamber 17, the air passage 19, the solenoid valve 20, the communication passage 81, the pipe 2b, and the rear chamber 5 are connected. Since it is carried out via a switch, there is no need for a connecting pipe for connecting the vehicle interior and the solenoid valve unlike the conventional negative pressure booster. That is, work efficiency can be improved without requiring a complicated process in the vehicle assembling process.

Therefore, it is possible to provide the negative pressure type booster 1 which improves the work efficiency of the assembly.

Further, during emergency braking, the input to the brake pedal 80, that is, the brake depression force is not sufficient. Therefore, when the negative pressure booster 1 is automatically operated to increase the brake output from FoX to FoX ', Is added to the normal brake output FoX in a supplementary manner, and the inclination of the operation line B at the time of sudden braking can be made larger than the inclination of the operation line A at the time of normal braking. An excellent negative pressure booster 1 can be provided.

Further, the auxiliary transformer chamber 17 is communicated with the rear chamber 5,
Since the output rod 11 is pressed by the auxiliary movable wall 15, the reaction force to the input rod 7 is reduced,
The operation responsiveness of the negative pressure booster 1 can be improved.

Further, since the electromagnetic valve 20 is configured to be operated in response to a sudden braking operation, in other words, in accordance with the situation of the vehicle, the operation of the electromagnetic valve 20 can be optimized. it can.

In the present embodiment, the auxiliary transformer chamber 17
Is connected to the rear chamber 5 through the air passage 19, the solenoid valve 20, the communication passage 81, and the pipe 2b.
When the auxiliary transformer chamber 17 and the rear chamber 5 are directly communicated with each other in the negative pressure booster 1 in a configuration without the solenoid valve 20, the configuration is the same as that of the negative pressure booster 1 shown in FIG. In FIG. 5, the same members as those of the negative pressure type booster 1 shown in FIGS. 1 to 3 are denoted by the same reference numerals.

As shown in FIG. 5, a passage 77 is provided integrally with the movable wall 3 and the diaphragm 16 and passes through the movable wall 3 and the diaphragm 16 in an airtight manner. Is connected to the rear chamber 5 through the airbag.
The operation of the vacuum booster 1 will be described. When the driver does not operate the brake pedal 80, which is a brake operation member of the vehicle, the vacuum booster 1 is in the state shown in FIG. 5, and the valve mechanism 9 is configured such that the atmospheric seal portion of the control valve 13 is an input member. 8, the rear chamber 5 is shut off from the atmosphere, the negative pressure seal portion of the control valve 13 is disengaged from the negative pressure valve seat of the power piston 6, and the front chamber 4 and the rear chamber 5 Are in the output reduction operation state in which the communication is performed. Therefore, the rear chamber 5 communicates with an intake manifold of a vehicle engine (not shown) that is a negative pressure source.

FIG. 6 is a characteristic diagram of the vacuum booster 1 of FIG. 5 in which the vertical axis represents output and the horizontal axis represents input. FIG.
As shown in FIG. 6, when the driver depresses the brake pedal 80 with, for example, the input FiY, the input rod 7 connected thereto moves forward (leftward in FIG. 5) by receiving the brake operation force. . Therefore, the input member 8 fixed to the input rod 7 also moves forward integrally with the input rod 7.

When the input member 8 is moved, the valve mechanism 9 is brought into contact with the atmospheric valve seat of the input member 8 from the state where the output of the valve mechanism 9 is reduced, and the negative pressure seal of the control valve 13 is moved. The rear chamber 5 comes into contact with the valve seat of the power piston 6 to enter an output holding state in which the rear chamber 5 is cut off from the front chamber 4 and the atmosphere.

Further, when the input member 8 moves forward, the engagement between the atmosphere seal portion of the control valve 13 and the atmosphere valve seat of the input member 8 is released, and the output increasing operation state in which the rear chamber 5 is communicated with the atmosphere is provided. Becomes Accordingly, a pressure difference is generated between the front chamber 4 and the rear chamber 5 due to the inflow of the atmosphere into the rear chamber 5, and the movable wall 3 loaded by the pressure difference and the power piston 6 connected thereto react. The amplified braking force is output to the output rod 11 via the disk 10.

In addition, air is introduced from the rear chamber 5 to the auxiliary transformer chamber 17 via the passage 77, and the front chamber 4 and the auxiliary transformer chamber 1 are introduced.
7, the auxiliary movable wall 15 loaded with the pressure difference presses the output rod 11 forward, and the forward movable force of the auxiliary movable wall 15 is generated as an output through the output rod 11. I do.

Thereafter, the valve mechanism 9 selects one of the output reduction operation state, the output holding operation state, and the output increase operation state by the reaction force received by the input rod 7 from the reaction disk 10 via the input member 8. The assisting force of the vacuum booster 1 is controlled according to the driver's braking force applied to the input rod 7.

The above-described power piston 6 and auxiliary movable wall 1
7 and the brake pedal 8
The brake operation force generated by operating 0 and transmitted to the input member 8 is applied to the reaction disk 10 and balanced. That is, the valve mechanism 9 enters the output holding operation state. When the brake operation force, that is, the input FiX and the reaction force from the reaction disk 10 are balanced, the output output from the output rod 11 is FoY shown in FIG.

That is, the auxiliary movable wall 15 and the auxiliary transformer chamber 17
As shown in FIG. 6, in the negative pressure booster having no, the output rod 11 is advanced by the forward force of the power piston 6 and the input to the input rod 7, and the output at the input FiY is FoY '. . However, in the negative pressure booster 1 of FIG. 5, the atmosphere is introduced into the auxiliary transformation chamber 17 from the rear chamber 5, so that in addition to the forward force of the power piston 6 and the input to the input rod 7, Since the advance force of the auxiliary movable wall 15 is applied to the output rod 11, the output is increased by the advance force of the auxiliary movable wall 15.

Accordingly, the auxiliary movable wall 15 and the auxiliary transformer chamber 1
Compared with the negative pressure booster without 7, the negative pressure booster 1 of FIG. 5 has an increased output of (FoY−Foy ′). Output of this increase (Foy-Foy ')
Is increased as the input increases. This is because the pressure in the rear chamber 5 increases as the input increases.
Is also increased in accordance with the increase of the input similarly.

The trajectory of the brake output acting on the output rod 11 with respect to the brake operating force (input) acting on the input rod 7 during normal operation of the vacuum booster 1 follows the operation line C in FIG.

According to the negative pressure booster 1, the auxiliary variable pressure chamber 17 communicates with the rear chamber 5, and the output rod 11 is pressed by the auxiliary movable wall 15. The force is reduced, and the operation responsiveness of the vacuum booster 1 can be improved.

Further, in the present embodiment, the auxiliary variable pressure chamber 17 is made communicable with the rear chamber 5 by the solenoid valve 20. However, the present invention is not particularly limited to this configuration. The same operation and effect can be obtained with the negative pressure booster of the present invention in which the communication between the auxiliary transformation chamber 17 and the rear chamber 5 is controlled by the device. This negative pressure type booster is shown in FIG.

In the vacuum booster 1 of FIG. 7, the same members as those of the present embodiment are denoted by the same reference numerals. The configuration other than the mechanical valve device 90 is substantially the same as that of the present embodiment, and a detailed description thereof will be omitted.

As shown in FIG. 7, the auxiliary transformer chamber 17 can communicate with the rear chamber 5 via a mechanical valve device 90. The valve device 90 extends in the front-rear direction (the left-right direction in FIG. 7), is disposed integrally with the movable wall 3 and the diaphragm 16, and hermetically penetrates the diaphragm 16 and the movable wall 3. 90a, and a valve body 9 disposed movably in the front-back direction or in the axial direction of the cylindrical portion 90a in the cylindrical portion 90a.
0b and a spring 90c for urging the valve body 90b backward (to the right in FIG. 7).

The valve body 90b abuts on a valve seat 90d formed on an inward flange portion provided at the rear opening of the cylindrical portion 90a, thereby blocking communication between the rear chamber 5 and the auxiliary transformer chamber 17. Then, the valve body 90b is separated from the valve seat 90d, thereby allowing communication between the rear chamber 5 and the auxiliary variable pressure chamber 17.

The key member 14 is located on the valve device 90 side (FIG. 7).
An engagement portion 14a is provided at an end portion (middle and lower side) of the valve device 90 and extends a predetermined amount in the front-rear direction and is engageable with the valve body 90b of the valve device 90. When the key member 14 is advanced with respect to the movable wall 3, the key member 14 is engaged with the valve body 90b, and the valve body 90b is moved forward.

Next, the operation will be described. The input / output characteristics of the vacuum booster 1 are substantially the same as those of the vacuum booster 1 shown in FIG. When the driver does not operate the brake pedal 80, which is a brake operation member of the vehicle, the vacuum booster 1 is in the state of FIG.
The atmosphere seal portion 13a is engaged with the atmosphere valve seat 8a of the input member 8, and the negative pressure seal portion 13b is not engaged with the negative pressure valve seat 6a of the power piston 6. Therefore, the rear chamber 5 is provided with an air path 6c, a clearance between the negative pressure valve seat 6a and the negative pressure seal portion 13b, a vacuum path 6b, and an intake manifold of a vehicle engine (not shown) that is a negative pressure source via the front chamber 4. Is in communication with

Further, in the valve device 90, the valve body 90b
The rear end of the rear chamber 5 is in contact with the engaging portion 14a of the key member 14, and the valve body 90b is separated from the valve seat 90d.
And the auxiliary transformer chamber 17 are communicated with each other. Therefore, the auxiliary transformer chamber 17 also exhibits a negative pressure similarly to the rear chamber 5.

As shown in FIGS. 4 and 7, the driver
For example, when the brake pedal 80 is depressed by the input FiX, the input rod 7 connected thereto moves forward (to the left in FIG. 7) by receiving the brake operation force. Therefore, the input member 8 fixed to the input rod 7 also moves forward integrally with the input rod 7.

The movement of the input member 8 causes the atmosphere seal portion 13a and the negative pressure seal portion 1 of the control valve 13 to move.
1 also moves forward in FIG. 1 together with the input member 8 by the urging force of the valve spring 13c, and the negative pressure seal portion 13b eventually comes into contact with the valve seat 6a of the power piston 6, and the rear chamber 5 is cut off from the front chamber 4. Therefore, communication with the negative pressure source of the vehicle is also cut off.

Further, when the input member 8 moves forward, the engagement between the atmosphere sealing portion 13a and the atmosphere valve seat 8a is released, and the rear chamber 5 is closed with the rear opening and the inside of the power piston 6 and the atmosphere sealing portion. It communicates with the atmosphere via a clearance between the portion 13a and the atmosphere valve seat 8a and the air path 6c. Therefore, the inflow of the atmosphere into the rear room 5 causes the front room 4 and the rear room 5
The movable wall 3 and the power piston 6 connected to the movable wall 3 receive a load due to the pressure difference.
The amplified braking force is output to the output rod 11 via the reaction disk 10.

When the input member 8, the power piston 6, and the movable wall 3 advance, the key member 14 moves the input member 8,
It retracts with respect to the power piston 6 and the movable wall 3. Therefore, since the key member 14 is retracted with respect to the valve device 90 provided on the movable wall 3, the valve body 90b receiving the urging force of the spring 90c is moved rearward to provide the valve seat 90d.
To sit down. When the valve body 90b is seated on the valve seat 90d, the communication between the rear chamber 5 and the auxiliary transformer chamber 17 is cut off, and the air flowing into the rear chamber 5 does not flow into the auxiliary transformer chamber 17.

Thereafter, the reaction force received by the input rod 7 from the reaction disk 10 via the input member 8 causes the atmospheric seal portion 13a and the atmospheric valve seat 8a, or the negative pressure seal portion 13b and the negative pressure valve seat 6a. Are selectively engaged, and the assisting force of the vacuum booster 1 is controlled in accordance with the driver's braking force applied to the input rod 7.

The reaction force due to the braking force of the power piston 6 and the brake operation force generated by operating the brake pedal 80 and transmitted to the input member 8 are applied to the reaction disk 10 and balanced.
When the braking operation force, that is, the input FiX and the reaction force from the reaction disk 10 are balanced, the output output from the output rod 11 is FoX shown in FIG.

That is, in the normal braking operation of the vacuum booster 1, the locus of the brake output acting on the output rod 11 with respect to the brake operating force (input) acting on the input rod 7 follows the operation line A in FIG. .

For example, when an obstacle appears in front of the vehicle and the driver suddenly depresses the brake pedal 80 with the input FiX faster than the depressing speed at the time of normal braking, a change occurs in the normal brake operation described above. Will happen. That is, a differential pressure is generated between the front chamber 4 and the rear chamber 5 by the operation of the valve mechanism 9 accompanying the movement of the input member 8, and the input member 8, the power piston 6, and the movable wall 3 are advanced.

At this time, when the brake pedal 80 is suddenly depressed, the key member 14 engages with the input member 8 and is moved forward by the input member 8, that is, the most advanced position with respect to the power piston 6, that is, FIG. The front surface of the key member 14 is held in contact with the front wall of the axial hole 6d of the power piston 6 as shown in FIG.

Accordingly, in the valve mechanism 90, since the valve element 90b is kept separated from the valve seat 90d, the auxiliary transformation chamber 17 and the rear chamber 5 are communicated with each other, and the air in the rear chamber 5 is released from the auxiliary transformation chamber 17d. Flows into. The introduction of air into the auxiliary transformer chamber 17 causes a pressure difference before and after the auxiliary movable wall 15, and the auxiliary movable wall 15 is moved forward while sliding on the inner periphery of the bead 16a.

As the auxiliary movable wall 15 moves,
The auxiliary movable wall 15 is engaged with the flange portion 11a of the output rod 11 to apply a load forward to the output rod 11, but since this load does not act on the reaction disk 10,
It does not become a reaction force to the input member 8, but is purely increased as the brake output.

Accordingly, the output of the vacuum booster 1 at this time is the sum of the input from the driver and the forward force of the power piston 6 and the forward force of the auxiliary movable wall 15 during normal operation. That is, the brake output acting on the output rod 11 changes from FoX to FoX 'for the same brake operation force FiX acting on the input rod 7 as compared to when the pressure in the auxiliary transformation chamber 17 is negative due to the introduction of the atmosphere into the auxiliary transformation chamber 17. Be increased.

That is, the locus of the brake output acting on the output rod 11 with respect to the brake operating force acting on the input rod 7 in the sudden braking operation of the negative pressure type booster 1 follows the operation line B in FIG.

When the driver of the vehicle judges that the necessity of the brake operation is no longer necessary and returns the brake pedal 80 of the vehicle, the input member 8 moves backward by retreating the input rod 7, and the atmosphere seal portion 13a is moved to the input member. 8 and the negative pressure seal portion 13b is separated from the negative pressure valve seat 6a of the power piston 6, so that the rear chamber 5 is cut off from the atmosphere and communicates with the front chamber 4.

Since the key member 14 can also be moved rearward by retreating the input member 8, the valve body 90b and the key member 14 are moved rearward following the retreat of the input member 8 by the urging force of the spring 90c. . The rearward movement of the valve body 90b causes the valve body 90b to be seated on the valve seat 90d, and
And the communication with the auxiliary transformation chamber 17 are interrupted.

Since the communication between the rear chamber 5 and the front chamber 4 causes the degree of negative pressure in the rear chamber 5 to increase again, the assisting force for the power piston 6 also decreases, and the reaction force from the master cylinder 70 decreases. The power piston 6 and the input rod 7 are moved backward toward the initial position by the return spring 18 in the booster 1. At this time, since the communication between the rear chamber 5 and the auxiliary transformer chamber 17 is interrupted by the valve mechanism 90, the atmosphere is still introduced into the auxiliary transformer chamber 19.

Accordingly, the output is reduced according to the diagram B in FIG. When the pedal 80 and the input rod 8 return to the initial positions, the valve mechanism 90 also returns to the initial state shown in FIG. 7, and the rear chamber 5 and the auxiliary transformer chamber 17 are communicated. Thereby, the atmosphere in the holding transformer chamber 17 is discharged to the negative pressure source via the rear chamber 5, the air path 6c, the space between the atmosphere seal portion 13a and the atmosphere valve seat 8a, the vacuum path 6b, and the front chamber 4. , The vacuum booster 1 completes its return stroke and completely returns to the initial state.

The difference between the output on the operation line A and the output on the operation line B (Fox'-Fox) increases as the input increases. This is because the pressure in the rear chamber 5 increases as the input increases, and the pressure in the auxiliary transformation chamber 15 communicating with the rear chamber 5 also increases as the input increases. .

According to the negative pressure booster 1 shown in FIG. 7, since the mechanical valve device 90 is used, an expensive solenoid valve 20 is used as in the negative pressure booster 1 of FIG. Since there is no need, and there is no need for control means for controlling the solenoid valve 20, cost can be reduced.

(Embodiment 2) FIG. 8 is a sectional view of a solenoid valve 20 of a negative pressure booster according to an embodiment of the present invention. The negative pressure booster of the present embodiment is substantially the same as the first embodiment except that a differential pressure valve 82 (second valve mechanism) is provided in the communication passage 81, and thus detailed description is omitted. I do. The same members as those in the first embodiment are denoted by the same reference numerals.

FIG. 9 is a characteristic diagram of the vacuum booster of FIG. 8 in which the vertical axis represents output and the horizontal axis represents input. As shown in FIGS. 8 and 9, a differential pressure valve 82 is provided in a communication passage 81 that connects the electromagnetic valve 20 and the rear chamber 5. The valve opening pressure of the differential pressure valve 82 is set to the pressure Pa in the rear chamber 5 at the time of the input Fia in FIG.

Next, the operation will be described. Since it is the same as the negative pressure booster 1 of the first embodiment except that the differential pressure valve 82 is added, FIGS. 1 to 3 will be used for convenience. Note that the normal brake operation is substantially the same as that of the first embodiment, and therefore the description is omitted, and only the sudden brake operation will be described.

As shown in FIGS. 1 to 3 and FIGS. 8 and 9, for example, an obstacle appears in front of the vehicle, and the driver inputs an input F.
When the brake pedal 80 is depressed at iZ, the controller 84 of the vehicle operates the brake pedal 80 at a pedal stroke speed equal to or higher than a certain threshold based on, for example, a pedal stroke value detected by a pedal stroke switch 83 attached to the brake pedal 80. When the necessity of emergency braking is determined by a method of determining that emergency braking is necessary when it is detected that power has been supplied, power is supplied to the electromagnetic solenoid 20e from a power source separately from the driver's brake operation. I do.

That is, in the negative pressure type booster 1, the normal operation by the driver's brake operation and the automatic operation by the operation of the solenoid valve 20 are performed. The electromagnetic solenoid 20e receiving the electric power generates an electromagnetic force to move the plunger 20f and the valve body 20h to the springs 20g and 20g.
It is moved rearward (rightward in FIG. 3) against the urging force of i.

As described above, the movement of the plunger 20f and the valve body 20h allows the auxiliary variable pressure chamber 17 to communicate with the rear chamber 5. When the driver depresses the brake pedal 80, the rear chamber 5 is communicated with the atmosphere, and the input F
At this time, the pressure Pb in the rear chamber 5 is higher than the pressure Pa in the rear chamber 5 when the output Foa is output with the input Fia.

Accordingly, the differential pressure valve 82 is opened, the rear chamber 5 and the auxiliary variable pressure chamber 17 are communicated, and the atmosphere is also introduced into the auxiliary variable pressure chamber 17. Due to the introduction of the atmosphere into the auxiliary transformer chamber 17, a pressure difference occurs before and after the auxiliary movable wall 15, and the auxiliary movable wall 15 is moved forward while sliding on the inner periphery of the bead 16a.

As the auxiliary movable wall 15 moves,
The auxiliary movable wall 15 is engaged with the flange portion 11a of the output rod 11 to apply a load forward to the output rod 11, but since this load does not act on the reaction disk 10,
It does not become a reaction force to the input member 8, but is purely increased as the brake output.

Accordingly, the output of the vacuum booster 1 at this time is the sum of the input from the driver and the forward force of the power piston 6 and the forward force of the auxiliary movable wall 15 during normal operation. That is, the brake output acting on the output rod 11 changes from FoZ to FoZ 'for the same brake operation force FiZ acting on the input rod 7 as compared to when the pressure in the auxiliary transformation chamber 17 is negative due to the introduction of the atmosphere into the auxiliary transformation chamber 17. Be increased.

The trajectory of the brake output acting on the output rod 11 with respect to the brake operating force acting on the input rod 7 in the sudden braking operation of the negative pressure booster 1 follows the operation line D in FIG. As is clear from FIG. 9, during the rapid braking operation, the output from the normal brake is increased after the input Fia. At this time, the pressure in the auxiliary transformation chamber 17 becomes (Pb−Pa).

When the driver of the vehicle judges that the necessity of the brake operation is no longer necessary and returns the brake pedal 80 of the vehicle, the input member 8 moves rearward by retreating the input rod 7, and the atmospheric seal portion 13a is moved to the input member. 8 and the negative pressure seal portion 13b is separated from the negative pressure valve seat 6a of the power piston 6, so that the rear chamber 5 is cut off from the atmosphere and communicates with the front chamber 4.

As a result, the degree of negative pressure in the rear chamber 5 increases again, so that the assisting force for the power piston 6 also decreases, and the reaction force from the master cylinder 70 and the return spring 18 in the booster 1 cause the power piston to move. 6 and the input rod 7 are moved backward. As the pressure in the rear chamber 5 drops, the differential pressure valve 82 is closed, and the communication between the auxiliary variable pressure chamber 17 and the rear chamber 5 is cut off. Therefore, the atmosphere is still introduced into the auxiliary transformer chamber 17, and the auxiliary transformer chamber 17
The pressure inside maintains (Pb-Pa). Accordingly, the output of the return stroke of the negative pressure booster 1 during the rapid braking operation is reduced according to the operation line E in FIG.

When the input rod 7 or the like completes the return stroke by releasing the input, at that time, the brake pedal 8 (not shown)
0, the microcomputer 84 confirms that the brake operation has been released by the conventional brake switch
Is detected and the supply of power from the power supply to the electromagnetic solenoid 20e is stopped, so that the electromagnetic solenoid 20e no longer generates an electromagnetic force to the plunger 20f,
f and the valve body 20h are returned forward by the biasing force of the springs 20g and 20i. When the plunger 20f moves forward, the auxiliary transformer chamber 17 communicates with the front chamber 4 again, and the air in the auxiliary transformer chamber 17 is exhausted to the negative pressure source via the front chamber 4 and the auxiliary movable wall 15 is returned by the return spring. 18, the engagement between the inner peripheral end thereof and the flange portion 11a of the output rod 11 is released, and the initial state is completely restored.

As described in the above embodiment, according to the present invention, the provision of the differential pressure valve 82 in the communication passage 80 makes it possible to exhibit an auxiliary output when the input is more than a predetermined input.
In particular, it is possible to provide the negative pressure booster 1 that is easily adapted to a brake system that attempts to provide an auxiliary output only to a high braking force.

Further, by appropriately setting the valve opening pressure of the differential pressure valve 82, a predetermined input can be easily set, so that a negative pressure booster having a simple configuration can be provided.

FIG. 10 is a schematic structural view of a negative pressure booster according to another embodiment of the present invention. The same components as those in the embodiment shown in FIG. 1 have the same reference numerals as those in FIG. Are attached to FIG. 10 and their description is omitted. In this embodiment, the operation switch 1 provided near the driver's seat
By the switching operation of 01 or the like, the electromagnetic valve 20 is operated via the controller 184 so as to communicate the auxiliary chamber and the rear chamber.
As a result, according to the present embodiment, the effectiveness of the brake can be set by the switching operation of the operation switch 101 or the like according to the driver's will. By improving the effectiveness, the brake operation can be performed more safely. The state of the switching operation of the operation switch 101 includes a case where the driver feels that the number of occupants has increased and the brake has become heavy, and a case where the driver has a weak brake operation force.

Although the present invention has been described based on the above embodiments, the present invention is not limited to the above embodiments but includes various embodiments according to the principle of the present invention.

[0113]

As described above, according to the first aspect of the present invention, it is possible to provide a negative pressure booster capable of communicating the rear chamber and the auxiliary chamber with a simple configuration.

Accordingly, it is possible to provide a negative pressure type booster which improves the work efficiency of assembly.

According to the invention of claim 2, in addition to the effect of the invention of claim 1, it is possible to provide a vacuum booster capable of increasing the output.

According to the third aspect of the invention, in addition to the effects of the second aspect, the introduction of air into the auxiliary chamber and the discharge of air from the auxiliary chamber can be performed with a simple configuration. This makes it possible to improve work efficiency and reduce costs.

According to the invention of claim 4, in addition to the effect of the invention of claim 2 or 3, it is possible to optimize the operation of the first valve mechanism.

According to the fifth aspect of the present invention, the braking operation can be performed more safely by improving the braking effect according to the driver's request.

According to the sixth aspect of the present invention, in addition to the effects of the second aspect of the present invention, in particular, a negative pressure type in which the output is increased when the input exceeds a predetermined value. It is possible to provide a booster.

[Brief description of the drawings]

FIG. 1 is a sectional view of a negative pressure booster 1 according to a first embodiment.

FIG. 2 is an enlarged view of a valve mechanism 9 in FIG. 1;

FIG. 3 is an enlarged view of a solenoid valve 20 in FIG. 1;

FIG. 4 is an input / output characteristic diagram of the vacuum booster 1 of FIG. 1;

FIG. 5 is a sectional view of a negative pressure booster 1 according to another embodiment.

FIG. 6 is an input / output characteristic diagram of the vacuum booster 1 of FIG.

FIG. 7 is a cross-sectional view of a negative pressure booster 1 according to another embodiment.

FIG. 8 is an enlarged view of a communication path 80 of the negative pressure booster of the second embodiment.

FIG. 9 is an input / output characteristic diagram of the vacuum booster according to the second embodiment.

FIG. 10 is a schematic configuration diagram of a negative pressure booster of another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Negative pressure type booster 2 Housing 3 Movable wall 4 Front room 5 Back room 6 Power piston 8 Input member 9 Valve mechanism 11 Output rod 15 Auxiliary movable wall 16 Diaphragm 17 Auxiliary transformer room 20 Solenoid valve 80 Brake pedal 81 Communication passage 82 Valve Device V1 Atmospheric valve V2 Negative pressure valve

Claims (6)

[Claims] 1. A housing defining at least one pressure space therein, and a front chamber installed in the housing so as to be able to advance and retreat with respect to the housing and communicating the pressure space with a negative pressure source. And a movable wall divided into the front chamber and a rear chamber selectively communicated with the atmosphere; a power piston coupled to the movable wall; and a forward and backward movement of the power piston inside the power piston. And an input member that is movable by operation of an operation member; and a negative pressure valve that communicates the rear chamber with the front chamber in response to the movement of the input member, and the rear chamber in response to the movement of the input member. A valve mechanism having an atmosphere valve communicating with the atmosphere, and an output member that is advanced by advancing the power piston with the movement of the movable wall and outputs a forward force of the power piston to outside the device. An auxiliary movable wall disposed in the front room so as to be movable in the front-rear direction and capable of moving the output member by engaging with the output member; and an auxiliary movable wall disposed in the front room and A negative pressure booster comprising: a partition member forming an auxiliary chamber therebetween; wherein the rear chamber and the auxiliary chamber can be communicated with each other. 2. The vehicle according to claim 1, further comprising a communication passage communicating the rear chamber and the auxiliary chamber, and a first valve mechanism capable of cutting off communication between the rear chamber and the auxiliary chamber via the communication passage. The negative pressure booster according to claim 1, wherein 3. The vacuum booster according to claim 2, wherein the first valve mechanism can selectively communicate the auxiliary chamber with the negative pressure source or the rear chamber. 4. The negative pressure booster according to claim 2, wherein the first valve mechanism is operated in accordance with a situation of a vehicle to communicate the auxiliary chamber and the rear chamber. apparatus. 5. The booster according to claim 2, wherein the first valve mechanism is operated by a driver to make the auxiliary chamber communicate with the rear chamber. apparatus. 6. The first valve mechanism and the rear chamber are disposed in the communication passage and between the first valve mechanism and the rear chamber, and communicate the first valve mechanism and the rear chamber when the rear chamber has a predetermined pressure. The negative pressure booster according to any one of claims 2 to 5, further comprising a second valve mechanism that performs the operation.